Apparatus for automatically centering moving objects



A. TEPLITZ April 6, 1954 APPARATUS FOR AUTOMATICALLY CENTERING MOVING OBJECTS Filed Feb. 1 1951 INVENTOR. ALFRED TEPLITZ BY ATTORNEY Patented Apr. 6, 1954 APPARATUS FOR AUTOMATICALLY CENTERING MOVING OBJECTS Alfred Teplitz, Pittsburgh, Pa., assignor to United States Steel Corporation, a corporation of New Jersey Application February 1, 1951, Serial No. 208,886

Claims. 1

This invention relates to apparatus for automatically centering and aligning moving objects, especially strip and strip-like materials. In the processing of metal strip, the strip is conveyed over rolls in the uncoiled condition. When the strip is conveyed over a roll to the processing equipment it is likely that the strip will be fed at a slight angle to the roll. Because of this, the strip will work its way across the face of the roll. In addition, the camber and/or lateral curvature which is present in the finished strip due to rolling difiiculties causes the strip edges and longitudinal center line to approach the roll at an angle, this also causing the strip to move across the face of the roll. In order to keep the strip in the desired path of travel, various expedients have been resorted to. One of the most common is the use of stationary or rotatable side guides against which the edges of the strip bear. In some instances side guides have been used in conjunction with looper pits to force the strip back on the desired center line. The use of abnormally high strip tension has also been tried in an attempt to keep the strip aligned. Another method of operation is to periodically slip or slue the strip back into its approximate proper position on the conveying roll. All of the above methods of centering strip tend to abrade and mutilate the strip edges and in some instances cause the edges of the strip to be stretched beyond the elastic limit of the metal. Diagonal or lateral surface scratches are also formed on finely finished flat products of all kinds, these scratches being detrimental to subsequent operations and together with edge damage result in the scrapping of a large percentage of the material being processed. The problems discussed above also exist in belt conveyors and drive belts used in conjunction with belt pulleys. If the belt is made of rubber or other relatively soft material, it is more easily damaged. In addition to the methods of aligning strip mentioned above, crown rolls have been used to center materials having a low modulus of elasticity such as textiles, rubber and composition belts.

One type of apparatus for centering and aligning strip is shown in the copending application to Lorig, Serial No. 145,648, filed February 23, 1950, now Patent No. 2,593,158. The apparatus shown therein is satisfactory for the purpose intended. This apparatus includes a pair of opposed spaced apart rotatable rolls over which the object passes with the rotating rims of the rolls being free to tilt and move toward each other progressively at the points or lines of contact with the moving object. The deflection of the rim of each of the rolls should be equal and their axes should be in a common plane. The various means for accomplishing this in the above identified Lorig patent are rather expensive and are so constructed that they may be damaged when used in the presence of dust, dirt, scale and the like.

It is therefore an object of my invention to provide an automatic centering roll in which the means for aligning the two halves of the roll are inexpensive to make and easy to maintain.

This and other objects will be more apparent after referring to the following specification and attached drawings, in which:

Figure l is a sectional view of my device; and

Figure 2 is a sectional view taken on the line II-II of Figure 1.

Referring more particularly to the drawings, the reference numerals 2 and 4 indicate a pair of opposed spaced apart rotatable frusto-conical rolls over which a strip or strip-like material S,

such as a conveyor belt, passes. The conical eiTect is exaggerated to show the aligning principle involved in the invention more clearly. In actual practice this effect can vary from zero to several degrees of angularity on the outer surfaces of the rolls. The rolls 2 and 4 are mounted on a rotatable shaft 6 which is mounted in bearings 8. If it is desired to drive the roll, the shaft 6 is provided with an extension as shown in broken line in Figure l. The rolls 2 and 4 have rim portions H] and I2, respectively, which are connected to inwardly extending web portions 14 and 58. The web portion 14 is welded to a hub portion it, which in turn is welded to the shaft 6. The web portion 5 5 is welded to a hub portion 20, which in turn is welded to the shaft 6. There is a space 22 between the rims I0 and I2 which is uniform around their periphery when the rolls are in their normal position. In order to assure that the deflections of the axes of the two frustoconical roll halves are equal with the axis lying in the same plane, disk-like web portions and 32 are welded to the rims It and 12, respectively, on their adjacent ends. These webs 3B and 32 extend radially inwardly toward the shaft 6 and are fastened to a hub portion 34 having a flange 35 extending outwardly between the webs 30 and 32. The webs 3!] and 32 are fastened to the hub 34 by means of bolts 38 passing through the webs 30 and 32 and the flange 36. If desired, the webs 39 and 32 can be welded to the hub 34 instead of bolted. Also, bronze bushing 40 may be provided on the inner portion of the hub 34. The internal 3 diameter of the hub 34 or the bushing 40 is greater than the outside diameter of the shaft '6 so that there is a space therebetween. The hub portion 34 contacts the shaft 6 to limit the amount of deflection of the rims I and I2.

The above described construction insures that the rolls 2 and 4 will rotate about a common axis in exact unison and that any deflection of either roll from its normal position will be exactly duplicated by a corresponding deflection of the other roll. Thus when pressure is applied to the rolls 2 and 4 by means of the strip S the equal deflections of the rolls causes them to tilt inwardly toward each other at the point of contact and outwardly at a point diametrically opposite as shown in Figure 1. The deflection of the rims of the rolls is made possible by the inherent flexibility of the webs I4 and I6. Because of this inward tilt, each of the rolls 2 and 4 tends to shift the strip passing thereover laterally toward the center of the composite roll. The forces available toeffect the shift toward the center are frictional and their magnitudes are therefore proportional to the amount of strip resting on the roll. If the moving strip 8, under uniform tension, is off-center laterally with the major portion thereof resting on roll 2 and the minor portion resting on roll 4, the centering forces of roll 2 will exceed those of roll 4 and the strip will be shifted laterally toward the center line of the roll assembly until the forces of roll 4 exactly balance those of roll 2. The movin strip will then remain centered.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. Apparatus for automatically positioning a moving object comprising a pair of opposed spaced-apart rotatable rolls over which the object passes, each of said rolls having a rim and a flexible web remote from their adjacent ends, a straight shaft for rotatably supporting said webs, a radially extending web portion fastened to each rim at their adjacent ends and extending inwardly toward said shaft, and means movable toward and away from said shaft for fastening the inner for positively causing one of said rims to rotate in the same direction and at the same angular velocity as the other rim, the rotating rims of said rolls being free to tilt and move toward each other progressively at the points of contact with the moving object on the approach side.

2. Apparatus for automatically positioning a moving object comprising a pair of opposed spaced-apart rotatable rolls over which the object passes, each of said rolls having a rim and a flexible web remote from their adjacent ends, a straight shaft for rotatably supporting said Webs, a radially extending web portion fastened to each rim at their adjacent ends and extending inends of said web portions together and wardly toward said shaft, and a hub portion adjacent said shaft and movable toward and away from said shaft and connecting the inner ends of said web portions for positively causing one of said rims to rotate in the same direction and at the same angular velocity as the other rim, said hub portion having an internal diameter slightly greater than the diameter of said shaft to limit the amount of deflection of said rims, the rotating rims of said rolls being free to tilt and move toward each other progressively at the points of contact with the moving object on the approach side.

8. Apparatus for automatically positioning a moving object comprising a pair of opposed spaced-apart rotatable rolls over which the object passes, a rotatable straight shaft, each of said rolls having a rim and a flexible web remote from their adjacent ends fastened to said shaft, a radially extending web portion fastened to each rim at their adjacent ends and extending inwardly toward said shaft, and means movable toward and away from said shaft for fastening the inner ends of said web portions together, the rotating rims of said rolls being free to tilt and move toward each other progressively at the points of contact with the moving object on the approach side.

4. Apparatus for positioning a moving object according to claim 3 in which the means for fastening the inner ends of said web portions together includes a hub portion surrounding said shaft, said hub portion having an internal diameter slightly greater than the diameter of said shaft to limit the amount of deflection of said rims.

5. Apparatus for automatically positioning a moving object comprising a pair of opposed spaced-apart rotatable rolls over which the object passes, each of said rolls having a rim and. a flexible web remote from their adjacent ends, means for rotatably supporting each of said webs, an extension for each of said last named means extending outwardly beyond the web of the adjacent roll and adapted to be supported in bearing means, a radially extending web portion fastened to each rim at their adjacent ends and extending inwardly toward the axes of said rolls, and means movable toward and away from the axes of said rolls for fastening the inner ends of said web portions together and for positively causing one of said rims to rotate in the same direction and at the same angular velocity as the other rim, the rotating rims of said rolls being free to tilt and move toward each other progressively at the points of contact with the moving object on the approach side.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 909,833 Vrooman Jan. 12, 1909 1,980,777 Z'ollinger Nov. 13, 1934 

